The deformation behaviour of cast austenitic corrosion-resistant steel type 20Mn–18Cr–3Ni–2Mo–0.4N in the temperature range 1000–1250 °C and strain rates in the range 0.1–10 s–1 has been studied. It is shown that the flow stresses drop with increasing temperature and decreasing strain rate in accordance with the change of the Ziner–Hollomon parameter of the temperature-velocity deformation regime. From the analysis of peak flow stresses, the value of the effective activation energy of hot deformation (Q = 490.3 kJ/mol) required for the calculation of the Ziner–Hollomon parameter is determined. An expression for the peak flow stress in the form of a hyperbolic function of the Ziner–Hollomon parameter was obtained. A comparative evaluation of hot plasticity of austenitic non-magnetic steel by finding the strain value corresponding to the appearance of the first macrocracks on the surface of the specimen is carried out.
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